Anesthesia, GeneralPhase 4NCT00482456
Homocysteine After Nitrous Oxide Anesthesia
A Phase 4 study testing Nitrous oxide in people with Anesthesia, General and Adverse Effects, run by Medical University of Vienna at 1 site in Austria.
Trial summary
Our study looks at the interaction of a common mutation in the MTHFR gene and the risk of developing higher homocysteine levels after nitrous oxide (N2O) anesthesia. Specifically, we want to test the hypothesis that healthy patients carrying the MTHFR 677C>T haplotype develop abnormal homocysteine levels after nitrous… Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Anesthesia, General, Adverse Effects, Nitrous Oxide
- What is being tested?
- Nitrous oxide
- How many people
- 140 participants
- Where
- 1 siteAustria
- Study dates
- Jan 2005to Mar 2007
- Phase
- Phase 4
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Patient scheduled for general anaesthesia (> 2 hours)
- Age > 18 years
- ASA status I-II
Who cannot join
- Pregnancy
- Age < 18 years
- contraindication against N2O: pneumothorax, mechanical bowel obstruction, middle ear occlusion, laparoscopic surgery
- recent use of vitamin preps (B12, B6, folate)
Trial locations and contacts
1 site in 1 country.
Austria1 site
Dept of Anesthesiology, Medical University of Vienna
Vienna, A-1090
About this study
Official title: Influence of the MTHFR 677C>T Mutation on Homocysteine Levels After Nitrous Oxide Anesthesia.
Our study looks at the interaction of a common mutation in the MTHFR gene and the risk of developing higher homocysteine levels after nitrous oxide (N2O) anesthesia.
Specifically, we want to test the hypothesis that healthy patients carrying the MTHFR 677C>T haplotype develop abnormal homocysteine levels after nitrous oxide anesthesia.
Read the detailed description
Nitrous oxide - laughing gas - is a widely used anaesthetic gas with many favourable but also some dangerous properties. Among the latter is the increase in homocysteine levels after nitrous oxide (N2O) exposure by inhibition of enzymes in the vitamin B12 pathway. Elevated homocysteine levels have been found to be an independent risk factor for ischemic events and are associated with an increased risk for perioperative myocardial ischemia. If a patient carries one or more loss-of-function mutations in enzymes of the methionine/homocysteine/folate pathway he is at an increased risk for hyperhomocysteinemia and if exposed to N2O might suffer severe, sometimes disastrous neurological damage. Recently, a case report in the New England Journal of Medicine reported the death of a child with an enzyme defect in the MTHFR gene after anaesthesia with nitrous oxide (NEJM 2003;349:45-50).
Thus, we are convinced that if we can determine the risk of patients who carry mutations in the MTHFR gene and undergo anaesthesia with N2O for developing pathological levels of homocysteine, we can add an important piece of information to the safety profile of N2O.
Our study tests the hypothesis that patients who carry the 677C<T mutation in the MTHFR gene (the most common mutation) have a higher risk of developing hyperhomocysteinemia after N2O anaesthesia.
- Conditions
- Anesthesia, General, Adverse Effects, Nitrous Oxide
- Being tested
- Nitrous oxide
- Keywords
- Nitrous oxide, Homocysteine, folate, vitamin B12
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Nitrous oxideDrug
What is being measured
The primary outcome is the main question the study is designed to answer.
Homocysteine levels dependent on MTHFR genotype
Measured: 2 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 Jun 2007 (estimated)
- Study startJan 2005
- Study completionMar 2007
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (2)Papers the sponsor has linked to this study.
- Other trials for Anesthesia, GeneralStudies of the same condition, open and under way.
- More trials run by Medical University of ViennaThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 4
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 140 participants (actual)
Sponsor and investigators
- Lead sponsor
- Medical University of Vienna
- Sponsor type
- University, hospital or other
- Investigators
- Peter Nagele, M.D., Principal investigator, Medical University of Vienna
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT00482456
- Sponsor's protocol ID
- EK 286/2004
- Status last verified
- May 2007
- First submitted
- 1 Jun 2007
- Last updated
- 5 Jun 2007
- Results posted
- No
- Data monitoring committee
- No
Publications
Nagele P, Zeugswetter B, Eberle C, Hupfl M, Mittlbock M, Fodinger M. A common gene variant in methionine synthase reductase is not associated with peak homocysteine concentrations after nitrous oxide anesthesia. Pharmacogenet Genomics. 2009 May;19(5):325-9. doi: 10.1097/FPC.0b013e328328d54c.
PubMed 19339913Nagele P, Zeugswetter B, Wiener C, Burger H, Hupfl M, Mittlbock M, Fodinger M. Influence of methylenetetrahydrofolate reductase gene polymorphisms on homocysteine concentrations after nitrous oxide anesthesia. Anesthesiology. 2008 Jul;109(1):36-43. doi: 10.1097/ALN.0b013e318178820b.
PubMed 18580170
Study at a glance
From the registry record, last updated by the sponsor on 5 Jun 2007. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Influence of the MTHFR 677C>T Mutation on Homocysteine Levels After Nitrous Oxide Anesthesia.
- ClinicalTrials.gov ID
- NCT00482456
- Acronym / sponsor ID
- EK 286/2004
- Conditions
- Anesthesia, General, Adverse Effects, Nitrous Oxide
- Keywords
- Nitrous oxide, Homocysteine, folate, vitamin B12
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 140 participants (actual)
- Lead sponsor
- Medical University of ViennaUniversity, hospital or other
- Study start
- Jan 2005
- Study completion
- Mar 2007 (actual)
- First posted
- 5 Jun 2007 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Our study looks at the interaction of a common mutation in the MTHFR gene and the risk of developing higher homocysteine levels after nitrous oxide (N2O) anesthesia.
Specifically, we want to test the hypothesis that healthy patients carrying the MTHFR 677C>T haplotype develop abnormal homocysteine levels after nitrous oxide anesthesia.
Detailed description
Nitrous oxide - laughing gas - is a widely used anaesthetic gas with many favourable but also some dangerous properties. Among the latter is the increase in homocysteine levels after nitrous oxide (N2O) exposure by inhibition of enzymes in the vitamin B12 pathway. Elevated homocysteine levels have been found to be an independent risk factor for ischemic events and are associated with an increased risk for perioperative myocardial ischemia. If a patient carries one or more loss-of-function mutations in enzymes of the methionine/homocysteine/folate pathway he is at an increased risk for hyperhomocysteinemia and if exposed to N2O might suffer severe, sometimes disastrous neurological damage. Recently, a case report in the New England Journal of Medicine reported the death of a child with an enzyme defect in the MTHFR gene after anaesthesia with nitrous oxide (NEJM 2003;349:45-50).
Thus, we are convinced that if we can determine the risk of patients who carry mutations in the MTHFR gene and undergo anaesthesia with N2O for developing pathological levels of homocysteine, we can add an important piece of information to the safety profile of N2O.
Our study tests the hypothesis that patients who carry the 677C<T mutation in the MTHFR gene (the most common mutation) have a higher risk of developing hyperhomocysteinemia after N2O anaesthesia.
Study design
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Patient scheduled for general anaesthesia (> 2 hours)
- Age > 18 years
- ASA status I-II
Key exclusion criteria (4 listed)
- Pregnancy
- Age < 18 years
- contraindication against N2O: pneumothorax, mechanical bowel obstruction, middle ear occlusion, laparoscopic surgery
- recent use of vitamin preps (B12, B6, folate)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Nitrous oxide | Drug | – |
Primary outcome
Homocysteine levels dependent on MTHFR genotype
Time frame: 2 years
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 5 Jun 2007.
- Derived from this study: PubMed 19339913Nagele P, Zeugswetter B, Eberle C, Hupfl M, Mittlbock M, Fodinger M. A common gene variant in methionine synthase reductase is not associated with peak homocysteine concentrations after nitrous oxide anesthesia. Pharmacogenet Genomics. 2009 May;19(5):325-9. doi: 10.1097/FPC.0b013e328328d54c.
- Derived from this study: PubMed 18580170Nagele P, Zeugswetter B, Wiener C, Burger H, Hupfl M, Mittlbock M, Fodinger M. Influence of methylenetetrahydrofolate reductase gene polymorphisms on homocysteine concentrations after nitrous oxide anesthesia. Anesthesiology. 2008 Jul;109(1):36-43. doi: 10.1097/ALN.0b013e318178820b.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Peter Nagele, M.D. principal investigator
Medical University of Vienna
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing Nitrous oxide in people with Anesthesia, General and Adverse Effects, run by Medical University of Vienna at 1 site in Austria.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 5 Jun 2007. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Austria. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Homocysteine levels dependent on MTHFR genotype (time frame: 2 years). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT00482456, which also lists 2 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 5 Jun 2007.